McLaren will announce Carlos Sainz as Fernando Alonso's replacement later this week, ESPN understands, opening the door for Pierre Gasly to step up to Red Bull next year.
On Tuesday McLaren confirmed Alonso will not continue in F1 beyond 2018, ending months of speculation about his future. McLaren had been making contingency plans for Alonso's departure and was in talks with Sainz and Daniel Ricciardo about a 2019 seat.
The Ricciardo talks were unsuccessful -- earlier this month the Australian announced his shock move to Renault for next year, taking Sainz's place as Nico Hulkenberg's teammate in the process.